Browsing by Author "Sampson, Gilbert Owiah"

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    Beta-Glucan Content In Tropical Maize Genotypes: Extractability, Structural Analysis, Rheology And Function
    (2013-12-16) Sampson, Gilbert Owiah
    Beta-glucan is a complex soluble dietary fiber with (1→3),(1→4)-β-D linkages in a repeating unit of cellotriosyl, cellotetraosyl glucose chains interspersed with β-(1→3) linkages, found mainly in the cell walls of cereal endosperm and specifically in oat and barley. Beta-glucan is known to impart some health benefits to consumers including lowering of blood glucose and cholesterol level, as well as prevention of colon cancer. Beta-glucan research has concentrated on oat, barley and wheat. The absence of these cereals in tropical West Africa necessitates an exploration into the use of cereals of tropical origin such as maize to identify their potential of being good sources of β-glucan. The objectives of this study weretoscreen tropical maize genotypes for β-glucan content,and evaluate their structure and functionality in food systems. In the present study, β-glucan contents ofseventeen Ghana maize genotypesviz., ‘Mamaba’, ‘Suwan 1 QPM’, ‘Obatanpa GH’, ‘Omankwa’,‘GH9’, ‘Catete’, ‘Dodzi’, ‘Okomasa’, ‘Aburohemaa’, ‘Abontem’, ‘SotuBaka’, ‘Dorke’, ‘Akposoe’, ‘Abeleehi’, ‘Safita 2’, ‘Ohawu Local’ and ‘Golden Jubilee’ were analyzed using hot water, acid, alkaline and alcohol-enzyme based extraction procedures. Gum content varied by extraction method and genotype. Hot water and alkaline procedures produced low extractability demonstrating gum yield ranging from 0 to 2.29 % and 0 to 22.12 %, respectively. Significantly higher gum yields were produced by the acid and alcohol-based enzyme extraction procedures. The acid treatment produced a mean yield of 45.97 % which was not significantly different from 39.97 % yield obtained by the alcohol-enzyme treatment (P>0.05). With regard to genotype, hybrid maize varieties contained the highest mean gum content of 31.83 % while the landraces contained lowest value of 19.11 %. Genotypes having the highest β-glucan content were 1.4 % for ‘Obatanpa GH’, 1.68 % for ‘Abeleehi’ and 2.56 % for ‘GH 9’. Gum content of kernels had positive correlations with protein and fibre but negative correlation with nitrogen free extract. Minimal levels of impurities in the form of starch, protein and fat were present in the gum isolates. Structural analysis of maize β-glucan by 13CNuclear Magnetic Resonannce produced chemical shifts similar to that of standard oat and barley spectra and characterized by slight displacements as upfield and downfield shifts. The aniline blue fluorescence microscopy revealed that β-1→3 branching in maize β-glucan was less than that in oat and was genotype dependent. ‘Abeleehi β-glucan demonstrated higher β-1→3 branching than ‘Obatanpa GH’ β-glucan. The flow behavior of 10 % maize β-glucan dispersion was pseudoplastic and non-Newtonian just as 5 % oatβ-glucan. High water binding capacity of maize β-glucan up to 232 % makes it a suitable ingredient in food products which should resist syneresis. Maize β-glucan was found to be a good fat replacer, replacing up to 15 % of fat in pie crust without compromising sensory attributes.
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    Glycemic Index of Five Ghanaian Corn and Cassava Staples
    (Journal of Food and Nutrition Research, 2019) Yeboah, Eunice Serwaa; Agbenorhevi, Jacob K.; Sampson, Gilbert Owiah; 0000-0002-8516-7656; 0000-0002-2175-4683
    Glycemic index (GI) quantifies and measures the blood glucose raising effect of a food containing a specific amount of carbohydrate. Due to this concerns have been raised on the quality of carbohydrate and the indices that influence its metabolism. The objective of study was to investigate the effect of processing on the glycemic index of five Ghanaian corn and cassava staples. The research design was a cross over trial. Ten healthy subjects consisting of five males and five females were included in the study. Study subjects were served 50g of pure glucose containing 50g of available carbohydrate and 200ml of pure water. Glucose which served as the reference food was given to subjects on two different occasions. The subjects were also served specific 50g of abolo, akple, kafa, local kokonteand processed kokonte on specific days. The glycemic index figures were assessed by using official methods and reported as mean for the ten study subjects. Locally made kokonte had the least GI of 7 followed by processed kokontewhich had a GI of 18 whiles kafa had a low GI of 29. Abolo had a medium GI value of 58 and akple also had a medium glycemic index value of 69. There was no significant difference between the GI of locally made kokonte and processed kokonte (p > 0.05) indicating processing had no significant effect on the GI of kokonte.
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    Pasting properties of starch-okra pectin mixed system
    (CyTA - Journal of Food, 2020) Bawa, Nadratu Musah; Agbenorhevi, Jacob K.; Kpodo, Fidelis M.; Sampson, Gilbert Owiah; 0000-0002-3861-779X; 0000-0002-8516-7656; 0000-0002-7949-0502; 0000-0002-2175-4683
    system. In this study, the effect of pectin extract from three okra genotypes (Agbagoma, Asontem, and Sengavi) at concentrations of 0%, 5%, 10%, and 15% on the pasting properties of starch were investigated. The pasting properties of the mixed systems were determined using the Rapid ViscoAnalyzer. The results showed that okra pectin decreased the peak viscosity and setback value of starch with the highest exhibited by Agbagoma and Asontem. The final viscosity of starch was increased in most samples except for 10–15% Agbagoma and 15% Asontem pectin systems. The peak time (3.84 − 6.84 min) increased with increasing okra pectin concentration. Pasting tempera ture for the mixed systems ranged from 51.24 o C (for 10% Sengavi) to 80.65°C (for 15% Agbagoma). Overall, okra pectin affected the pasting properties of starch and decreased starch retrogradation.
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    Pasting properties of starch-okra pectin mixed system
    (CyTA - Journal of Food, 2020) Bawa, Nadratu Musah; Agbenorhevi, Jacob K.; Kpodo, Fidelis M.; Sampson, Gilbert Owiah; 0000-0002-8516-7656
    The pasting properties of starch are influenced by the starch-hydrocolloid interaction in the mixed system. In this study, the effect of pectin extract from three okra genotypes (Agbagoma, Asontem, and Sengavi) at concentrations of 0%, 5%, 10%, and 15% on the pasting properties of starch were investigated. The pasting properties of the mixed systems were determined using the Rapid ViscoAnalyzer. The results showed that okra pectin decreased the peak viscosity and setback value of starch with the highest exhibited by Agbagoma and Asontem. The final viscosity of starch was increased in most samples except for 10–15% Agbagoma and 15% Asontem pectin systems. The peak time (3.84 − 6.84 min) increased with increasing okra pectin concentration. Pasting temperature for the mixed systems ranged from 51.24 o C (for 10% Sengavi) to 80.65°C (for 15% Agbagoma). Overall, okra pectin affected the pasting properties of starch and decreased starch retrogradation.
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    Proximate Composition and Functional Properties of Some New Groundnut Accessions
    (Journal of Food Security, 2017) Khalid, Alhassan; Agbenorhevi, Jacob K.; Asibuo, James Y.; Sampson, Gilbert Owiah; 0000-0002-5960-9529; 0000-0002-5960-9529; 000-0002-2175-4683
    Ten new accessions of groundnut (Arachis hypogea) were oven dried and processed into full fat powdered forms and analysed for the proximate and functional properties using AOAC official methods. The crude protein ranged 20.7-25.3%, crude fat 31- 46%, ash 1.2-2.3%, crude fiber 1.4 -3.9%, carbohydrate 21-37% and moisture 4.9-6.8 %. Energy values of the groundnut accessions were between 525 kcal/100g and 606 kcal/100g. The ash, moisture, carbohydrate, fat and fiber values of all groundnut accessions proved to be significantly different whereas there was no significant difference amongst the protein values at p ≤ 0.05. The bulk density ranged between 0.63 g/cm3and 0.88 g/cm3 whereas water absorption capacities were between 20 % and 30 %. Swelling power ranged from 2.98 g/g to 4.18g/g and solubility index was between 26.5% and 57% with no significant difference at p ≤ 0.05. Foaming capacity ranged from 4.0-16.2 % and stability 94-100%. Samples showed a significant difference in terms of bulk density at p ≤ 0.05. The relatively high protein content of all the accessions as well as their functional properties make them a valuable protein supplement in weaning foods as well as the treatment of protein energy malnutrition cases.
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    Proximate Composition and Functional Properties of Some New Groundnut Accessions
    (Journal of Food Security, 2017) Khalid, Alhassan; Agbenorhevi, Jacob K.; Asibuo, James Y.; Sampson, Gilbert Owiah; 0000-0002-8516-7656; 0000-0002-5960-9529; 0000-0002-2175-4683
    Ten new accessions of groundnut (Arachis hypogea) were oven dried and processed into full fat powdered forms and analysed for the proximate and functional properties using AOAC official methods. The crude protein ranged 20.7-25.3%, crude fat 31- 46%, ash 1.2-2.3%, crude fiber 1.4 -3.9%, carbohydrate 21-37% and moisture 4.9-6.8 %. Energy values of the groundnut accessions were between 525 kcal/100g and 606 kcal/100g. The ash, moisture, carbohydrate, fat and fiber values of all groundnut accessions proved to be significantly different whereas there was no significant difference amongst the protein values at p ≤ 0.05. The bulk density ranged between 0.63 g/cm3 and 0.88 g/cm3 whereas water absorption capacities were between 20 % and 30 %. Swelling power ranged from 2.98 g/g to 4.18g/g and solubility index was between 26.5% and 57% with no significant difference at p ≤ 0.05. Foaming capacity ranged from 4.0-16.2 % and stability 94-100%. Samples showed a significant difference in terms of bulk density at p ≤ 0.05. The relatively high protein content of all the accessions as well as their functional properties make them a valuable protein supplement in weaning foods as well as the treatment of protein energy malnutrition cases.